The list needs some updating....

I have a 2000 2.7.

I replaced the battery some time ago with a Duralast 48-D.

It has been dependable for at least 5 years, but it might be 8.

In any event, the battery has been complaining lately, and today it was flat. I am going to charge it just to see, but I am pretty sure I am due for a replacement.

Autozone no longer makes the 48-D.

I seem to recall various fitment issues based upon the recommended batteries.

What is the current model that folks are using?

Thanks in advance....

[sites.google.com]

Happy Boxstering
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

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Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

My autozone Duralast battery lasted quite some time. So I am a believer and would be happy to replace.

That said, they no longer make the 48-D or 48-DL according to the sales guy I spoke to. They have a new substitute.

I suspect it is trial and error and I can just drive over there and change the thing, but it is always better to know in advance.

If you can find a desulfating charger the battery will do a much better job at holding a charge than if you just charge it normally.

You're welcome to use mine if you're in the NYC area.

I never heard of that we will see. I clutch started the car and drove around for a while, then left it to idle for an hour or so. I will see today if it held the charge.

I really don't hink it will. The battery IS several years old and it DOES have long periods of little use in the winter. (and now with 3 kids - other times too).

The problem with long periods of time of little use is that it causes a buildup on the plates. That effectively reduces the ability of the battery to hold and deliver charge. Desulfation can do miracles on a "dead" battery.

I've been told by Porsche roadside assistance (FWIW) that the Boxster's battery does not charge while the car idles. My experience is consistent with that.

I know 12 Volts is a nominal figure, but I don't think the battery is being discharged at idle. Maybe the energy recuperation stuff has something to do with it. Also, wasn't the move from generators to alternators partly to increase charging ability?

Quote
Laz
I know 12 Volts is a nominal figure, but I don't think the battery is being discharged at idle. Maybe the energy recuperation stuff has something to do with it. Also, wasn't the move from generators to alternators partly to increase charging ability?

I'll have to watch my volt reading at idle to see what it gives me. In online info I've found, the consensus seems to be that a fully charged battery (without the engine running) should be 12.6 - 12.7 Volts. The chart in the link below seems to be typical of the information I've found.

While driving, I do generally notice the Voltage reading in the 13.7 V range, but have seen it as high as 14.8 V. That last reading seems to be after the car has been sitting a few days, so must be the charging voltage. I've also seen it as low as 12.6 V when driving (cruising at steady speed). Likely because the alternator is not charging a fully charged battery, or simply maintaining it.

This past week, when I parked the car after a long drive on the weekend, reading was 12.7 V. Next day, I washed and detailed exterior and interior where I raised / lowered the top and spoiler several times. The car wasn't driven for 4 days. Before starting it the 5th day, I checked and found a reading of 12.3 V, which according to chart in the link below, indicated the battery was about 50% discharged. Not sure what % of that would be attributed to raising / lowering the top, but I would think that puts a fairly heavy load on the battery.

[carbatteryonline.net]

I asked the dealer if that was too much, and they said it's not a concern. It might've been during multi-mile downgrades and possible regeneration from the brakes.

This morning, before starting the car, gauge showed 12.5 V, down from 12.7 when I parked it 4 days earlier. While driving, I was getting readings of 14.7 - 14.8 V indicating it was charging. Sitting at a traffic light, idling, it was still reading 14.8 V.

So it appears, at least with the 981, that the battery is being charged at idle when the battery isn't fully charged.

Quote
Roger987
I've been told by Porsche roadside assistance (FWIW) that the Boxster's battery does not charge while the car idles. My experience is consistent with that.

This sounds right based on what's in the Service Technik book. Charging occurs when under braking, etc., as to maximize efficiency.

I left the car idling for a couple hours with a couple of spins onto and off the hwy in the mix.

The battery seems to have recovered for the moment. Today will be the test. With all the rain, I did not drive it all week.

You shouldn't feel too bad. A five year run on a car battery is really good. Eight is amazing. The Porsche car salesman will probably tell you not to bother to replace the battery and to just buy a new Boxster instead.

... he always said that he would never replace a battery because he would replace the car first.
He had many great cars in his life, but he never found true love with a single one.
Too sad.
Happy Porscheing
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna